Fume-hood for chemical laboratories.



S. E. COLEMAN.

PUME HOOD FOB CHEMICAL LABORATORIES.

APPLICATION FILED NOV. 12, 1913.

Patented Nov. 17, 1914.

2 8HEBTS-SHEET 1.

\Y 1 TN I'ISSES:

S. E. COLEMAN.

FUMB HOOD FOB. CHEMICAL LABORATORIES.

APPLICATION FILED NOV. 12, 1913- 1,117,551, Patented Nov. 17, 1914.

2 SHEETS-SEEET 2.

WI'TN ESSES:

SILAS E. COLEMAN, OF OAKLAND, CALIFORNIA.

FUME-I-IOOD FOR CHEMICAL LABORATORIES.

Specification of Letters Patent.

Patented Nov. 1'7, 1914.

Application filed November 12, 1913. Serial No. 800,506.

To all whom it may concern Be it known that I, SILAs E. CoLEMAN, a citizen of the United States, residing at Oakland, in the county of Alameda and State of California, have invented new and useful Improvements in Fume-Hoods for Chemical Laboratories, of which the following is a specification.

This invention relates to improvements in fume hoods for chemical laboratories.

The object of the invention is to provide a convenient and efficient fume hood to be permanently or otherwise mounted on the chemical laboratory table, and connected with a mechanical exhaust system of pipes, exhaust fan, motor, etc., whereby the noxious or otherwise objectionable. fumes generated in the progress of chemical experiments may be promptly and effectively removed, and the contamination of the air of the laboratory prevented as fully as may be possible.

A further object is to provide a fume hood which, owing to its construction and method of operation, may be made of small size, to the end that each laboratory table may be equipped with a sufficient number of said hoods to provide either a single hood or an individual compartment of a multiple hood for each pupil regularly working at said'table at any one time; and to the further end that such individual accommodations may be provided without necessitating either an increase in the size of the table or a decrease in the number of pupils regularly accommodated at the same.

A further object is to provide a fume hood, which, owing to its small size and simplicity of construction, is of moderate cost, and whose installation in considerable numbers in a single laboratory is therefore economically as well as operatively practicable.

Conformably with these objects, the invention consists of certain novel features of construction, combination, and arrangement of parts. as will be hereinafter described and claimed.

The present embodiment of my invention is in three forms, which I designate respectively the single fume hood, the double fume hood, and the quadruple fume hood. All forms of the hood are constructed of metal,

ings: 2 is a single compartment hood, closed on four sides by a top 3, the sides 4: and back 5. At the bottom of the side and rear walls, flanges 6 are turned in bymeans of which the hood may be permanently fastened to the table top. At the front edges of the side walls, flanges 7 are formed, which stiffen the walls and serve as guides for the drop doors or shutters 8 and 9. The drop doors are provided with lateral grooves 10, and may be about one-half as long as the open front of the hood, which engage the flanges 7, Fig. l. The doors are each slidably adjustable to any desired height along the guides 7, and for moving them knobs 11 are provided. The upper door 8 is provided with a corrugated yieldable metal strip 12, extending approximately from top to bottom of the door on its rear side. The wired front edge 13 of the top 3 of the hood engages with the corrugations of said strip, as the door is moved up, and the successive depressions of the strip, together with the wired edge, serve as a series of positive, automatic stops to support the door at any desired elevation, Fig. 2. When the doors are dropped to their respective lowest positions, Fig. 3, they completely close the front of the hood. At the rear of the hood is an exhaust pipe 14 which may extend downward through the table top and connect below the table top with the exhaust.

pipe system 15 of the table and the laboratory. The exhaust pipe opens at the upper end and is provided with a drop cover 16, which is hinged at the top edge, and which isheld in the open position by means of a spring catch 17.

The fume hood, as above described, is designed to provide a heat-resisting inclosure of metal, connected with a mechanical exhaust system, the form and size of said inclosure being such as to properly accommodate within it an evaporating dish D, Fig. 2, or other vessel, together with such portions of an iron ring R and the base S of a. ring stand as may be necessary in supporting the vessel, and also together with a burner B for heating the vessel and its contents, all substantially as shown in Fig. 2. Said hood is further designed to provide an inclosure of suitable form and size, in vhich bottles, flasks, or other vessels may be )liLCBd for the collection of noxious gases and vapors, and for experiments with the same, the hood being operatively connected with a mechanical exhaust system, and of such construction as to effect the removal of said gases and vapors, and of all objectionable fumes generated within it. llhe said hood is provided with means as the doors 8-9 for reducing its free front opening or openings to a total area small enough to insure a positive inward draft at all of said openings during the progress of any and all experiments within the hood, thus preventing the escape of fumes from within the hood through any of said openings, while at the same time permitting the necessary adjustment of supports, burner, vessel, etc., being well shown in Fig. 2. lit is desirable that said hood be provided with means by which it may be cut off from the exhaust system when the hood is not in use, to the end that other hoods which are in use have the maximum benefit of the exhaust. This condition of the hood may be effected either by dropping the cover 16 over the exhaust pipe opening, or by completely closing the front of the hood by means of 'the sliding drop doors, as in Fig. 3.

lit is to be observed that the construction and use of the hood, as above illustrated and described, tulfils all requirements of a convenient and efficient fume hood tor the individual use of pupils in performing chemical experiments, without the necessity oi the hood being large enough to include gas and water outlets, or to admit of the complete inclosure and allow manipulation within the hood of ring stands and other bulky apparatus. With the two adjustable sliding doors, the apparatus is essentially a closed hood, since the free openings necessary for the adjustment of supports, etc, are no larger than are also necessary to provide a. suitable current of air for the exhaust.

Fig. 5 shows a cross section of a double chamber fume hood, and Fig. 6 a vertical medial section through the two compartments of said hood, one on opposite sides or the common exhaust pipe 15'. Fig. 7 shows a quadruple fume hood in cross section, and vertical section of the same taken in the plane of a partition 5 of Fig. 7.

As shown in Figs. 6 and Z, the two-compartment or double fume hood is essentially, both in construction and operation the combination, of two of the single hoods built back to back, and having one and the same exhaust pipe for the two compartments. The oblique elliptical opening of the exhaust pipe into each compartment is provided with a hinged cover 10, as in the single hood. The parts of Figs. 7 and 8 are designated by the same numbers as the like parts in Figs. 1 to 6, inclusive. The double hood is normally placed with its partition on the mid-line between the two sides of a laboratory table. lhe two compartments are used from opposite sides of the table, and are wholly independent of each other in their operation.

As shown in Figs. 7 and 8, the tour-compartment or quadruple fume hood is essentially, both in construction and operation, a combination of two of the .double hoods, with the exception that the four compartments are connected with one and the same exhaust pipe 15" The oblique opening of the exhaust pipe into each compartment of the hood is provided with a cover 16", turning on a hinge 16 and held in the open position by a spring catch 17. respects the parts of each compartment are like the corresponding parts of the single hood, and in the figures the like parts are designated by the same numbers.

Various changes in the -form, proportion, and minor details of construction may be resorted to without departiru from the principles or sacrificing any or the advantages of this invention.

Having thus described my invention what ll claim and desire to secure by Letters Patent, is zl. A multiple compartment fume hood for chemical laboratory tables having an exhaust pipe opening directly into the compartments of the hood and a c over or valve to the exhaust outlet in each compartment, by means of which any or all compartments may be connected with or cut off from the exhaust.

2. A fume hood consisting of a casing having a partition on its interior which divides the casing into a plurality oil compartments, and a vertical exhaust pipe which has one side extending on one side face of the partition and having its opposite side extending on the opposite side face of the partition, the upper end of the exhaust pipe being open and terminating below the top of the hood so as to communicate with each oi? the compartments which the partition forms, and means cooperating with the upper end of the pipe and operating in the space between the upper end of the pipe and in other llli the top of the hood to enable a compartment to be cut-ofi' from said exhaust pipe independent of the other compartment.

3. A fume hood consisting of a casing having an exhaust outlet, a divided door at the front of the casing, the door divisions being independently movable whereby same may be adjusted so as to be spaced from the bottom of the hood to allow part of chemical apparatus to be projected from the exterior of the casing into the interior of the latter and to also allow another part of the said apparatus to be projected into the casing interior at a point between the top and the bottom of the casin said doors also enabling adjustable air in ets for the casing interior to be provided.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

SILAS E. COLEMAN.

Witnesses:

W. W. HEALLEY, M. KANDESER. 

